Is porting my motor worth it?

[jdh250r]

i ordered the trx9 from ESR and i have an LRD adjustable with a 38mm PWK and VF3's. I wanted more mid/bottom so he's gonna go for a midrange port and cut me a race gas dome, also he reshaped my pump gas dome.

[albertp86]

Thanks Dman250r. It's good to hear feedback. Did you port the cylinder after riding the 310 for a while? Meaning, do you have something to compare before and after? Thanks

[jdh250r]

i rode my 310 on the trx9 for a year so i'll also be able to give ya feedback

[Dman250r]

Thanks Dman250r. It's good to hear feedback. Did you port the cylinder after riding the 310 for a while? Meaning, do you have something to compare before and after? Thanks

No. Both Carlos and Neil suggested I do that, but I just didn't have the patience. Are you looking at high compression and race gas too or just an mx/xc port?

[albertp86]

I am looking for it to pull harder in the dunes. I ran a race dome and it had tons of bottom end but it slowed me down on the top end. Don't know why. I switched back to the pump dome and she still has a lot of bottom and picked up on top as well. Just looking to improve a bit. Nothing too crazy. Seems to me that the pump dome let's the motor rev easier up top. I could be wrong but that was my take on it. I was running vp110 so I know the fuel was not the issue.

[acecarlos]

Within a given range, lower compression allows the engine to rev easier than higher compression does, specially if the set-up or porting is off. A well ported & flowed cylinder will do both; pull like a train on the low-mid range and rev to the moon.

Now, I see you have a 310PV + 3MM, and based on what you described happened between the Pump & Race Domes, I would bet a dollar your engine is not properly set-up to work as it should with a +3MM stroke. The simptons you described are typical of what results from adding stroke and not porting to match properly...at least that is my opinion. You will almost always have a decent bottom end due to the PV, the top end Rev is what needs work...

Carlos.